Insulation resistance testers (also called digital insulation resistance testers) can be used to determine the integrity of windings or cables in motors, transformers, switchgear, and electrical installations. The test method is determined by the type of equipment under test and the reason for the test. For example, when testing cables or switchgear (low-capacitance devices), the time-varying capacitance leakage and absorption of leakage current become unimportant and drop to zero almost immediately.

The stable conductive leakage current is reached almost immediately (one minute or less), which provides beautiful conditions for point reading/short-time resistance testing. On the other hand, when the device under test is a long-running cable, large motor or generator (high-capacitance equipment), time-dependent currents will last for several hours, and these currents will cause the meter readings to change continuously, making it impossible Obtain accurate and stable readings. This situation can be overcome by using a test that establishes a trend between readings, such as a step voltage test or a dielectric absorption test. These tests do not rely on a single reading, but on a collection of relative readings. Performing these tests on low-capacitance devices is a waste of time, because the current that changes over time decays quickly, causing all measurement results to be the same.

Installation test of insulation resistance tester

The most important reason for testing insulation is to ensure the safety of the public and individuals. By conducting a high DC voltage test between unpowered current-carrying (heat), grounding and grounding conductors, the possibility of life-threatening short circuits or short circuits to ground can be eliminated. This test is usually performed after the initial installation of the equipment. This process will protect the system from wiring errors and equipment defects, and will ensure high-quality installation, customer satisfaction, and prevent fire or electric shock.

Maintenance test of insulation resistance tester

The second most important reason for insulation testing is to protect and extend the life of electrical systems and motors. Over the years, electrical systems have been exposed to environmental factors such as dust, grease, temperature, pressure, and vibration. These conditions can lead to insulation failure, resulting in production losses and even fires. Regular maintenance tests can provide valuable information about the deteriorating state of the system and help predict the possible failures of the system. Correcting problems can not only make the system trouble-free, but also extend the service life of various equipment.